I. Field
The present disclosure relates generally to wireless communications, and more specifically to techniques for conducting paging in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication services; for instance, voice, video, packet data, broadcast, and messaging services can be provided via such wireless communication systems. These systems can be multiple-access systems that are capable of supporting communication for multiple terminals by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. In such a system, each terminal can communicate with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link can be established via a single-in-single-out (SISO), multiple-in-signal-out (MISO), or a multiple-in-multiple-out (MIMO) system.
Voice Call Continuity (VCC) is a process by which a voice call at a wireless terminal is maintained as the wireless terminal moves from the coverage of one cell to the coverage of another cell. Conventionally, a VCC application server (AS) is utilized in a wireless communication system to support VCC by anchoring a voice call at a wireless terminal and managing handover of the voice call between cells. To establish a voice call at a wireless terminal in a system that supports VCC, a VCC AS can initiate paging of the wireless terminal.
To establish a VCC-supported call on a network that supports voice communication in the packet switched (PS) radio domain (e.g., through Voice over Internet Protocol (VoIP)) that can be relocated to a network that supports only circuit switched (CS) voice communication or vice versa, the VCC AS may not have knowledge of whether a base station serving a particular wireless terminal supports PS voice communication. As a result, a VCC AS is conventionally required in such a situation to page indiscriminately through both the CS and PS domains. In turn, this can cause a wireless terminal to receive two ostensibly independent pages simultaneously, which can be falsely interpreted by the terminal as a conflict. Further, if a terminal receives a PS page while being served by an access point that supports low-rate PS services but does not support PS voice communication, the terminal may respond to the page and unsuccessfully attempt to establish a PS call. In such a situation, it is desirable for the terminal to establish a CS call rather than a PS call, but conventionally there is no way to ensure that a CS page will arrive at the terminal before a PS page.
Accordingly, there exists a need in the art for techniques by which a VCC-supported voice call can be established in a network containing access point(s) that can support PS voice communication as well as access point(s) that can support only CS voice communication.